Heating appliances of this type have a wide range of uses, i.e. for example in switch cabinets in order to maintain the electronics contained therein at operating temperature even when the external temperature is low or to avoid corresponding formation of condensate. They are produced at different thermal outputs in large quantities. The commercially accepted price is relatively low; in addition, many known appliances have high power consumption. There is increasing demand for environmentally acceptable products.
Known appliances are expensive and complex to manufacture. In particular, the operating costs are usually high on account of the high power consumption. Environmentally polluting materials are also often used for appliances of this type.